Photo: Jared Winkler · CC BY-SA 4.0Winter nights in Arion are colder than in 93% of U.S. towns
Midsummer highs settle at about 85°. Precipitation peaks in June and eases off in January. It is a dry place: less rain and snow fall here than on 80% of U.S. towns. Tender plants can go out after about April 27; in half of years the first frost comes by October 11.
A year in Arion at a glance
Each month’s typical high and low, and what it brings.
What stands out about Arion’s climate
Compared with towns across the U.S., with Arion’s place in Iowa beside it.
What a year in Arion feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 166 frost-free days a year
In half of years the last 32° night comes by April 27 and the first by October 11. Frost and day counts come from NOAA’s station at Denison, IA, 9 miles from the town’s center, 260 ft higher.
The 2023 USDA map puts Arion’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −15°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 35 inches of snow a winter
Snow, measured at Denison, IA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 33 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 103 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Arion
90% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Denison, IA.
Living with Arion’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
166 frost-free days in zone 5b. The last frost comes by Apr 27 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 11.
Months with highs of 62–84° and lows of 40° or more: May, June, August and September.
Parks & trails →Of the yearly building losses FEMA expects in Arion from natural hazards, river flooding is the largest share (35%); heat waves, cold waves, winter storms and ice storms together are 8%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Arion and similar climates
TownRatings has no climate map of the towns around Arion yet.
Climates most like Arion’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Arion, IA | 11° | 85° | 33" | 35" |
| Rockford, IL | 13° | 84° | 37" | 37" |
| Prairie du Chien, WI | 10° | 83° | 37" | 34" |
| Winona, MN | 8° | 83° | 36" | 38" |
| Mount Pleasant, MI | 15° | 83° | 33" | 39" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Arion averaged 0.8° warmer than the 1900s. The biggest change is in December (+2.2°).
A smaller shift than in 88% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Arion compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Arion’s place among Iowa’s.
Arion weather by month
Highs, lows and precipitation from NOAA’s grid at Arion’s center; snow, wet days and snow on the ground from Denison, IA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 29° | 11° | 0.8" | 8.1" | 6 | 17 | 11° – 33° |
| February | 34° | 15° | 1.0" | 9.2" | 7 | 16 | 14° – 34° |
| March | 48° | 27° | 1.9" | 4.7" | 8 | 7 | 30° – 53° |
| April | 61° | 37° | 3.4" | 1.6" | 10 | 1 | 41° – 55° |
| May | 72° | 48° | 4.7" | 0.1" | 13 | 0 | 54° – 67° |
| June | 82° | 59° | 4.9" | 0.0" | 11 | 0 | 66° – 76° |
| July | 85° | 63° | 4.0" | 0.0" | 10 | 0 | 68° – 80° |
| August | 82° | 60° | 4.4" | 0.0" | 10 | 0 | 66° – 77° |
| September | 76° | 52° | 3.3" | 0.0" | 8 | 0 | 58° – 69° |
| October | 63° | 39° | 2.5" | 0.5" | 8 | 0 | 44° – 56° |
| November | 47° | 26° | 1.5" | 2.4" | 6 | 3 | 27° – 48° |
| December | 34° | 16° | 1.2" | 7.9" | 6 | 11 | 10° – 31° |
| Year | 59° | 38° | 33.4" | 34.5" | 103 | 56 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 30° to 53°. June is the most reliable, staying within 9°.
Where Arion’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Arion’s center.
- Snow: Denison, IA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Denison, IA, 9 miles from the town’s center, 260 ft higher; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Arion’s climate
What is the weather like in Arion?
A typical July afternoon reaches 85°, a January night drops to 11°, and about 35 inches of snow falls in a normal winter. Colder January nights than 93% of U.S. towns; cooler July afternoons than 54% of U.S. towns.
How cold does it get in Arion in winter?
January nights average 11°. About 149 nights a year reach 32° or below and 17 reach 0° or below. In the coldest January of the last 30 years the month averaged 11°.
How much snow does Arion get?
About 35 inches in a normal winter at Denison, IA, most of it in February, with snow on the ground about 56 days a year.
How hot does it get in Arion?
July, with a typical high of 85° and a low of 63°. About 14 days a year reach 90° (Denison, IA).
When is the first and last frost in Arion?
In half of years the last spring frost (32°) comes by April 27 and the first fall frost by October 11, about 166 frost-free days, at Denison, IA.
What growing zone is Arion in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −15°.
What is the best time of year to visit Arion?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Arion getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 88% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Arion.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.